(i) Technical Field
The invention relates generally to adjustment drives, for example a drive apparatus for adjusting windows, sliding roofs, and the like of motor vehicles.
(ii) Background Information
German patent document DE-A1 29 11 024 discloses a motor vehicle window drive apparatus having a ratchet-type locking mechanism. A pivoting detent pawl mounted on an entraining element is biased under spring pressure toward a toothed rim. When a motor used to drive the mechanism is in operation, the detent pawl is free to move relative to the toothed rim. In one direction to raise the window, the detent pawl slides over the teeth of the toothed rim without locking, and in the opposite direction to lower the window, a stop cam acts against the spring pressure on the detent pawl to disengage it from the toothed rim. When the motor is not in operation, the detent pawl engages the toothed rim to prevent unwanted movement. Tangential play between the entraining element and a motor-driven worm gear is possible only in the context of elastic resilience of a damping element interposed between the worm gear and the entraining element.